When pod vegetables such as green beans are commercially harvested by machines, the pods frequently remain in clusters of two or more pods still fastened together by stem sections, and also include single pods attached to undesirable stem sections. A necessary step in the processing of such vegetables is the subdivision of these clusters and the removal of excess stem sections so that individual pods may be further processed without waste or trash. Machines designed to subdivide such clusters are commonly referred to as declustering machines. Such a machine is described in Weirauch, U.S. Pat. No. 3,405,750.
The Weirauch machine is representative of a type of pod vegetable processing machine in which the vegetable is tumbled inside of a rotating drum. Such drums commonly comprise a multiplicity of cylindrical sections with slots penetrating their outer walls. The slots are adapted to allow the ends of pods to protrude as they tumble in the rotating drum. Knives sliding on the rotating exterior surface of the cylindrical sections cut off the protruding undesirable blossom and stem ends, a process generally known as "snipping." A multiplicity of such cylindrical sections are fastened end-to-end to form the drum. Partitions within the drum are adapted to maximize the likelihood that pods being processed in the drum will in fact come into contact with the outer cylindrical sections so that the ends of the pods may protrude through the slots for snipping. A passageway in each partition allows the vegetable pods being processed to migrate down the length of the rotating drum when one end of the drum is elevated.
The partitions in the Weirauch machine are further adapted to engage any clusters of pods present in the machine and thrust the stems of the clusters against rotating declusterer disc assemblies adjacent to the sides of the partitions, to subdivide the clusters. To accomplish this purpose the edges of the circular passages of the Weirauch partitions are serrated by a series of notches into which the stems of the clusters may drop and become engaged. Another partition for a Weirauch type declusterer machine is described in Kumandan, U.S. Pat. No. 4,131,062. The passages in the Kumandan partitions are in the form of straight sided geometric shapes (an octagon is preferred) with specially designed notches at the intersection of the primary edges of the passageways and specially designed intermediate notches recessed within each of the primary edges. The notches engage pod clusters by way of a "snagging" effect as the partition is rotated through the vegetable mass.
Both the Weirauch and Kumandan partitions are designed to allow clusters engaged in the partition notches to be efficiently presented to declusterer disc assemblies for subdivision. The declusterer disc assembly shown in the Weirauch patent consists of two annular discs attached in a parallel fashion directly to a hub consisting of an axial section of circular tubing. The gap between the discs is fixed so as to be only slightly wider than the thickness of the associated notched partition edge to cause the discs and the partition to cooperate in a cutting relationship. Cluster stems are snagged by the partition notches and drawn between the parallel inner surfaces of the discs to sever the stems and free individual beans from the cluster. A plurality of declusterer disc assemblies may be mounted in an axially spaced manner on a circular shaft to form a declusterer comb as shown in FIG. 4 of the Weirauch patent. The declusterer disc assemblies may be held in a fixed position relative to the rotating partitions or, preferably, be rotated in the same manner as the partitions.
An operating problem that has been experienced with declusterer discs in accordance with the Weirauch design is that residual stem material becomes packed into the gap between the discs during operation of the machine, thereby increasing interference with the associated partition, spreading the discs and damaging the machine. Cleaning the spaces is difficult and time consuming, because of limited access to the disc assemblies. As a result, the declustering efficiency of the machine is not optimized.